Syringe

The missing dns-preheating daemon!
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Table of Contents

1. About The Project
2. Usage
3. Building
4. Monitoring & Metrics
5. Screenshots
6. Roadmap
7. Contributing

About The Project

During my quest to improve customer satisfaction, I asked myself how I may reduce the impact on customers dns response times during frequent component replacements (the component is a dns-resolver in this case if you mind asking).

Background: In a setup where services are announced via bgp, any component is suspect to hot replacement. DNS-resolver heavily rely on their query cache to answer valid or bogus queries as fast as possible. When spinning up a new server, it may experience full production traffic without a filled cache. This may lead to clogged query upstreams or even a brief period of blacklisting if a common upstream resolver (e.g. tiering) is used. To address this issue, this project was started.

Side note: This is also a "java programmer"'s first take on a go application which is perfect for this use-case.

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Usage

NOTE: Please download/build a specific release first See Releases for prebuilt artifacts

Usage is as easy as:

# linux/mac
./syringe PARAMS
# windows
.\syringe.exe PARAMS

Command-Line Parameters (PARAMS)

Flag	Value	Default	Description
-help	(none)		Print a help message showing all available flags
-config	Valid Path	syringe.yml	Use the specified config instead of the default

Configuration (syringe.yml)

For informations regarding the configuration file, please refer to the Documentation

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Building

Getting started is easy as there are many methods to start right away!

• First clone the repository

  git clone https://github.com/TCMPK syringe

• cd into the cloned directory

  cd syringe

docker-compose

Preprequisites

• docker
• docker-compose

Build & Run the application

• Build the image and start an attached compose-stack

  docker-compose up # will do a "docker-compose build" if the image does not exist

• Open http://localhost:8000/docs/index.html which which should present you with the swagger-api documentation. Now you can get your hands on

Docker

Preprequisites

• docker

Build & Run the application

• Build the image

  docker build -t syringe . # build the image named "syringe" in the current directory .

• Start the container and attach

  # The api is listining on 0.0.0.0:8000 so we need to map the port
  docker run -it -p 8000:8000 syringe # start the container and attach stdout/stdin 

• Open http://localhost:8000/docs/index.html which which should present you with the swagger-api documentation. Now you can get your hands on

Bare Metal (Linux, Mac, Windows)

Preprequisites

• golang
• gcc

Build & Run the application

• Download all modules

  go mod download

• Build

  # build linux/mac
  go build -o syringe
  # windows 
  go build -o syringe.exe

• Run

  # linux/mac
  ./syringe
  # windows
  .\syringe.exe

• Open http://localhost:8000/docs/index.html which which should present you with the swagger-api documentation. Now you can get your hands on

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Monitoring & Metrics

Metrics are exposed as Prometheus metrics are available via localhost:8000/metrics. Visualization is also provided as Grafana dashboard in the grafana/dashboard.json folder.

Setup

• Install Prometheus or use a Docker container
• Install Grafana or use a Docker container
• Setup a Prometheus scrape job and adjust target as for your deployment

  scrape_configs:
    - job_name: 'syringe scrape'
      scrape_interval: 5s
      static_configs:
        - targets: 
          - 'localhost:8000'

• Add the Prometheus data source to Grafana
• Import the Grafana dashboard from the grafana/dashboard.json file
• Select the correct Data Source (uses default by default) in the syringe dashboard if multiple data sources are present

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Screenshots

Grafana Dashboard grafana/dashboard.json

Swagger Documentation http://localhost:8000/docs/index.html

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Roadmap

See the open issues for a full list of proposed features (and known issues).

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Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

1. Fork the Project
2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
3. Commit your Changes (git commit -m 'Add some AmazingFeature')
4. Push to the Branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

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License

Distributed under the Apache license 2.0.

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Contact

Peter Klein - [email protected]

Project Link: https://github.com/TCMPK/syringe

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